1. Field of the Invention
This invention relates to a gaseous fuel compression and control system for gas turbine engine.
2. Description of the Prior Art
A conventional gaseous fuel compression and control system for gas turbine engine is disclosed in, for example, U.S. Pat. No. 4,536,126 or U.S. Pat. No. 5,103,629. This conventional gaseous fuel control system includes a source of compressed gaseous fuel and many control valves which are interposed between the source of compressed gaseous fuel and a combustion chamber of a gas turbine and which control gas fuel flow to the combustion chamber in response to computer-generated control signals (for starting, for controlling engine speed and output power and so on). In general, the source of compressed gaseous fuel has always included a compressor of the reciprocating type. These traditionally specialised compressors are employed for duties which require the raising of the pressure of a flammable gas such as natural gas for combustion in the gas turbine.
Reciprocating compressors normally operate at fixed speed and displacement. Therefore, in order to regulate fuel flow to a gas turbine to control the gas turbine output power and speed, a complex control system using the above mentioned control valves is required. Furthermore, a high pressure accumulator which is maintained between high and low pressure limits is also needed for controlling the fuel flow.
There are many mechanical connections in the construction of a reciprocating compressor. There are also many connections in the inlet and outlet pipework and associated components of the above control systems. The integrity of these connections is threatened by the intense vibrations associated with reciprocating compressors. Therefore, the possibility of gas leaks occurring is relatively high.